Heretofore, various automated packaging machines have been known for packaging materials in packet form. Generally, these machines have been of the type where a freely unwinding continuous sheet of paper, foil, or the like is sealed along two edges leaving an open edge into which measured amounts of material are deposited. Thereafter, the open edge is sealed, usually by a smooth or serrated surfaced bar, and a severing operation is performed.
However, such an arrangement provides distinct disadvantages. In the first place, this arrangement results in the formation of rectangularly shaped packets. The rectangular shape requires double sealing. Three edges are sealed before filling, and the fourth edge is sealed after filling. This double sealing method is difficult to use if the desired shape of the packets is a shape other than rectangular, for example, circular. The use of such a double sealing method is also less efficient than a single sealing method. Another disadvantage is that the machines are not adaptable to readily change from producing a packet of one size and shape to a packet of a different shape or size without extensive retooling of the machine. Still another disadvantage is that packaging machines which operate horizontally require more factory floor space than those which operate vertically. A problem also results from the use of such an arrangement in that packaging material freely unwinds from a roll. The speed and tension of the unwinding packaging material cannot be controlled when permitted to freely unwind. This is particularly disadvantageous when there are two sheets of packaging material which must interface at a particular point. Also, freely unwinding packaging material cannot be stopped simultaneously when the machine is turned off. Lastly, there is a decrease in production output in the above mentioned arrangement because it is not designed to produce multiple horizontal rows, as well as multiple vertical rows of packets.
Accordingly, the aforementioned arrangement has presented distinct disadvantages in the automated packaging of granular materials.
Other arrangements have been developed in the area of automated packaging. For example, U.S. Pat. Nos. 3,633,331, 4,004,399, 4,209,960, 4,215,524, 4,437,294, 4,631,905, and 4,967,537 are all directed to various methods of automated packaging. A brief description of these methods is now given.
U.S. Pat. No. 3,633,331 to Reichlin discloses a rotating vane-type feeder for dispensing granular material between two webs of packaging material. The filling and sealing of the packages occurs at a sealing station.
U.S. Pat. No. 4,004,399 to Borrello discloses a form-fill-seal apparatus in which two webs of packaging material are united by rotating sealing nip rolls that provide a longitudinal seam forming a tube. Material is deposited into the tube by a rotating feeding vane. The tube is subsequently sealed transversely to provide discrete packets by nipping sealing surfaces.
U.S. Pat. No. 4,209,960 to Deutschlander et al. discloses an apparatus which weighs articles to form uniformly weighing stacks of articles that are subsequently packaged in cartons.
U.S. Pat. No. 4,215,524 to Saylor discloses the use of longitudinal seam forming nip rolls and transverse sealing means for forming a chain of packets from two webs of packaging material which is then cut by a separate cutter to form discrete packets.
U.S. Pat. No. 4,437,294 to Romagnoli discloses a two web form-fill-seal apparatus using a pocket roller dispensing fluent product on to one, horizontal, web and a pair of opposed pocketed rollers for placing another web over the material carrying web and forming and sealing the two webs into individual packets.
U.S. Pat. No. 4,631,905 to Maloney discloses a form-fill-seal apparatus in which two webs of packaging material are formed into packets by transverse and longitudinal seam forming nip rolls.
U.S. Pat. No. 4,967,537 to Moore discloses an apparatus for packaging wherein a plurality of sealed interconnected compartments are formed by sealing together two separate webs.
It should be noted that the citation of any reference herein should not be deemed an admission that such reference is available as prior art to the present invention.